/*
 * Copyright (c) 2005 JGoodies Karsten Lentzsch. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * 
 *  o Redistributions of source code must retain the above copyright notice, 
 *    this list of conditions and the following disclaimer. 
 *     
 *  o Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution. 
 *     
 *  o Neither the name of JGoodies Karsten Lentzsch nor the names of 
 *    its contributors may be used to endorse or promote products derived 
 *    from this software without specific prior written permission. 
 *     
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

package org.pushingpixels.substance.internal.contrib.jgoodies.looks.common;

import java.awt.Component;

import javax.swing.*;

import org.pushingpixels.lafwidget.utils.LookUtils;
import org.pushingpixels.substance.internal.contrib.jgoodies.looks.Options;

/**
 * The JGoodies Looks implementation of <code>PopupFactory</code>. Adds a drop
 * shadow border to all popups except ComboBox popups. It is installed by the
 * JGoodies Plastic L&amp;F, as well as by the JGoodies Windows L&amp;F during
 * the Look&amp;Feel initialization, see
 * {@link com.jgoodies.looks.plastic.PlasticLookAndFeel#initialize} and
 * {@link com.jgoodies.looks.windows.WindowsLookAndFeel#initialize}.
 * <p>
 * 
 * This factory shall not be used on platforms that provide native drop shadows,
 * such as the Mac OS X. Therefore the invocation of the {@link #install()}
 * method will have no effect on such platforms.
 * <p>
 * 
 * <strong>Note:</strong> To be used in a sandbox environment, this PopupFactory
 * requires two AWT permissions: <code>createRobot</code> and
 * <code>readDisplayPixels</code>. The reason for it is, that in the case of the
 * heavy weight popups this PopupFactory uses a Robot to snapshot the screen
 * background to simulate the drop shadow effect.
 * 
 * @author Andrej Golovnin
 * @author Karsten Lentzsch
 * 
 * @see java.awt.AWTPermission
 * @see java.awt.Robot
 * @see javax.swing.Popup
 * @see LookAndFeel#initialize
 * @see LookAndFeel#uninitialize
 */
public final class ShadowPopupFactory extends PopupFactory {

	/**
	 * In the case of heavy weight popups, snapshots of the screen background
	 * will be stored as client properties of the popup contents' parent. These
	 * snapshots will be used by the popup border to simulate the drop shadow
	 * effect. The two following constants define the names of these client
	 * properties.
	 * 
	 * @see com.jgoodies.looks.common.ShadowPopupBorder
	 */
	static final String PROP_HORIZONTAL_BACKGROUND = "jgoodies.hShadowBg";
	static final String PROP_VERTICAL_BACKGROUND = "jgoodies.vShadowBg";

	/**
	 * The PopupFactory used before this PopupFactory has been installed in
	 * <code>#install</code>. Used to restored the original state in
	 * <code>#uninstall</code>.
	 */
	private final PopupFactory storedFactory;

	// Instance Creation ******************************************************

	private ShadowPopupFactory(PopupFactory storedFactory) {
		this.storedFactory = storedFactory;
	}

	// API ********************************************************************

	/**
	 * Installs the ShadowPopupFactory as the shared popup factory on non-Mac
	 * platforms. Also stores the previously set factory, so that it can be
	 * restored in <code>#uninstall</code>.
	 * <p>
	 * 
	 * In some Mac Java environments the popup factory throws a
	 * NullPointerException when we call <code>#getPopup</code>.
	 * <p>
	 * 
	 * TODO: The Mac case shows that we may have problems replacing non
	 * PopupFactory instances. Therefore we should consider replacing only
	 * instances of PopupFactory.
	 * 
	 * @see #uninstall()
	 */
	public static void install() {
		if (LookUtils.IS_OS_MAC) {
			return;
		}

		PopupFactory factory = PopupFactory.getSharedInstance();
		if (factory instanceof ShadowPopupFactory)
			return;

		PopupFactory.setSharedInstance(new ShadowPopupFactory(factory));
	}

	/**
	 * Uninstalls the ShadowPopupFactory and restores the original popup factory
	 * as the new shared popup factory.
	 * 
	 * @see #install()
	 */
	public static void uninstall() {
		PopupFactory factory = PopupFactory.getSharedInstance();
		if (!(factory instanceof ShadowPopupFactory))
			return;

		PopupFactory stored = ((ShadowPopupFactory) factory).storedFactory;
		PopupFactory.setSharedInstance(stored);
	}

	/**
	 * Creates a <code>Popup</code> for the Component <code>owner</code>
	 * containing the Component <code>contents</code>. In addition to the
	 * superclass behavior, we try to return a Popup that has a drop shadow, if
	 * popup drop shadows are active - as returned by
	 * <code>Options#isPopupDropShadowActive</code>.
	 * <p>
	 * 
	 * <code>owner</code> is used to determine which <code>Window</code> the new
	 * <code>Popup</code> will parent the <code>Component</code> the
	 * <code>Popup</code> creates to. A null <code>owner</code> implies there is
	 * no valid parent. <code>x</code> and <code>y</code> specify the preferred
	 * initial location to place the <code>Popup</code> at. Based on screen
	 * size, or other paramaters, the <code>Popup</code> may not display at
	 * <code>x</code> and <code>y</code>.
	 * <p>
	 * 
	 * We invoke the super <code>#getPopup</code>, not the one in the stored
	 * factory, because the popup type is set in this instance, not in the
	 * stored one.
	 * 
	 * @param owner
	 *            Component mouse coordinates are relative to, may be null
	 * @param contents
	 *            Contents of the Popup
	 * @param x
	 *            Initial x screen coordinate
	 * @param y
	 *            Initial y screen coordinate
	 * @return Popup containing Contents
	 * @throws IllegalArgumentException
	 *             if contents is null
	 * 
	 * @see Options#isPopupDropShadowActive()
	 */
	@Override
	public Popup getPopup(Component owner, Component contents, int x, int y)
			throws IllegalArgumentException {
		Popup popup = super.getPopup(owner, contents, x, y);
		return Options.isPopupDropShadowActive() ? ShadowPopup.getInstance(
				owner, contents, x, y, popup) : popup;
	}

}
